Internal reflections in optical fibres have several applications, such as for sensor purposes and for verifying the function of a fibre optical network. Light transmitted in an optical fibre is reflected at the reflector and the reflected light can be detected.
Optical reflectors for generating internal reflections in optical fibres and methods for producing such reflectors are previously known from U.S. Pat. Nos. 4,892,388 and 4,400,056. However, the prior methods are rather complicated and there is thus a need for providing simple production methods for reflectors in optical fibres.
In the patent U.S. Pat. No. 5,210,801 optical components are disclosed constructed of flat wave guides or wave guides having rectangular cross-sections, where a cavity is arranged located adjacent a wave guide core, however never so located that the material of the wave guide core is located directly at the cavity. The production of the components is made by means of the conventional, process technological, relatively complicated and costly methods which are used for manufacturing electronic integrated circuits and optical planar circuits.